Manufacture of electric contactor prongs



Feb. 11, 1941. F. R. REUTTER 2,231,348

MANUFACTURE OF ELECTRIC CONTACTOR PRONGS Filed June 10, 1939 Iig.4.-.

INVENTOR Frederick R.Reutter TTORNEY Patented Feb. 11, 1941 MANUFACTUREOF ELECTRIC CONTACTOR PRONGS Frederick R. Reutter, Waterbury, Conm,assignor to Scovill Manufacturing Company, Waterbury, Conn, acorporation of Connecticut Application June -10, 1939, Serial No.278,451

4 Claims.

This invention relates to the manufacture of electric contactor prongsand particularly to the method 01 forming serrations or projections onthe prongs for the purpose of providing a secure anchorage for the prongwhen inserted into an electric plug made of rubber or a similarmaterial.

The main object of this invention is to make a contactor prong for theabove use in which the original metal stock from which the prong is madeis no wider than the finished width of the prong, and by a swagingoperation portions of the stock are forced outwardly beyond the originalwidth of the prong blank and constitute a series of serrations orteeth-like projections.

15 This invention is an improvement on my copending application filedJanuary 11, 1938, Serial Number 184,399. Other objects and advantages ofthe invention will be apparent from the following description whichtaken in connection 20 with the accompanying drawing discloses two formsof my invention.

In the drawing:

Fig. 1 is a longitudinal sectional view through the body portion of anelectric plug showing a contactor prong in its finished state embeddedtherewithin.

Fig. 2 is a plan view of a prong member, per se, as it appears after thefirst blanking operation showing a series of notches cut into the orig-30 inal side edge of the blank to produce the desired number of teeth.

Fig. 3 is a similar view showing the blank after a secondary operationof swaging is performed to force the teeth outwardly'beyond the original35 width of the prong blank.

Fig. 4 is a transverse sectional view through the toothed portion of theblank taken along the line 4-4 of Fig. 3.

In the drawing, the numeral indicates a 40 plug body which in this casemay be of the soft rubber type having a socket II provided therein toreceive the con'tactorprong I2 in its finished state. The socket Hpreferably is somewhat restricted relative to the dimensions of thecross 45 section of the prong so as to cause the prong to be insertedtherewithin only by a forced fit.

The manner in which the prong I2 is produced is best shown in Figs. 2and 3 wherein the original blank is indicated by the numeral I3. This 50original blank l3 out of which the prong I2 is fabricated is of the samewidth as the metal stock from which the blank is cut, the strip stockbeing shown in dotted outline in Figure 2 and indicated by the letter K.

55 Adjacent one end of the blank l'3 a series of notches M are cut infrom the opposite longi tudinal edges; specifically these notches'arecut so that one edge of the notch is disposed substantiallyperpendicular to the longitudinal axis of the blank while the other edgeis inclined to the 5 axis so as to produce a seriesof serrations orsawlike teeth 15, the points of which are still within the originalblank width. Along with the operation of cutting out the notches, otherpiercings may be efiected at the same time, as for instance, 10 theterminal lug notch i6 provided at the inner end of the blank and twopiercings l1 and I8.

In order to force the teeth I 5 outwardly beyond the blank width, one ormore elongated depressions or sockets l9 are formed within the stock atthe base of the teeth l5. These sockets may be struck inwardly from oneflat plane of the blank 13 or preferably they are struck inwardly fromthe two opposite sides of the blank in a manner as best shown in Fig. 4;The sockets 2o l9 are produced by a punching operation and are so formedas to cause the metal of the blank 13 to be displaced and driftedoutwardly beyond the original, opposite longitudinal edges of saidblank. Thus the teeth l5 will be forced outwardly from their originalposition so that they project beyond the original blank width as shownin Fig. 3. Simultaneously with the forming of the depressions l9, theouter end 20, the notch l6 and the piercing l8 may be slightly bevelledso as to give the blank a more finished appearance.

While there has been shown only one form of the invention, it is to beunderstood that this invention is not limited thereto but may comprehendother methods of construction without de- 5 parting from the spirit ofthe invention.

- What I claim is:

1. The method of producing a conductor prong for an electric connectorplug comprising cutting a longitudinal blank from a strip of metal ofthe same width, cutting a series of notches in from the longitudinaledge of said blank to form a plurality of teeth on a plane common withthe blank, and swaging in a direction perpendicular to the plane of theblank an elongated socket into said blank directly in back of all ofsaid notches and thereby causing all the teeth to be forced outwardlybeyond the original longitudinal edge of said blank.

2. The method of forming a conductor prong for an electric connectorplug comprising cutting a longitudinal blank from a strip of metal ofthe same width, cutting a series of notches in from the oppositelongitudinal edges of said blank to form a plurality of sharp teeth on aplane come mon with the blank, and swaging in a direction perpendicularto the plane of the blank elongated sockets into said blank directly inback of all of said notches and thereby causing the opposite sets ofteeth to be forced outward-1y beyond the original longitudinal edges ofsaid blank.

3. The method of producing a conductor prong for an electric connectorplug comprising cutting a longitudinal blank from a strip of metal ofthe same width, cutting a series of notches in from the oppositelongitudinal edges of said blank to form a plurality of sharp teeth on aplane common with the blank, and swaging elongated sockets adjacent thebase of said notches in from both opposite sides of said blank and in adirection perpendicular thereto and thereby causing the opposite sets ofteeth to be forced outwardly beyond the original longitudinal edge ofsaid blank.

4. The method of producing a conductor prong for an electric connectorplug comprising cutting a longitudinal blank from a strip of metal ofthe same width, cutting a series of notches in from one longitudinaledge of said blank of a character to provide a plurality of buttressshaped teeth on a plane common with the blank, and swaging an elongatedsocket into said blank at the base of said notches and in a directionperpendicular to the plane of said blank and thereby cause all the teethto be forced outwardly beyond the original longitudinal edge of saidblank.

FREDERICK R. REU'I'IER.

